test_2d.composite.canvas.difference.html

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<!DOCTYPE HTML>↩

<title>Canvas test: 2d.composite.canvas.xor</title>↩

<script src="/tests/SimpleTest/SimpleTest.js"></script>↩

<link rel="stylesheet" href="/tests/SimpleTest/test.css">↩

<body>↩

<canvas id="c" width="100" height="50"><p class="fallback">FAIL (fallback content)</p></canvas>↩

<script>↩

function isPixel(ctx, x,y, r,g,b,a, pos, colour, d) {↩

    var pixel = ctx.getImageData(x, y, 1, 1);↩

    var pr = pixel.data[0],↩

        pg = pixel.data[1],↩

        pb = pixel.data[2],↩

        pa = pixel.data[3];↩

    ok(r-d <= pr && pr <= r+d &&↩

       g-d <= pg && pg <= g+d &&↩

       b-d <= pb && pb <= b+d &&↩

       a-d <= pa && pa <= a+d,↩

       "pixel "+pos+" is "+pr+","+pg+","+pb+","+pa+"; expected "+colour+" +/- "+d);↩

}↩

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SimpleTest.waitForExplicitFinish();↩

addLoadEvent(function () {↩

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var canvas = document.getElementById('c');↩

var ctx = canvas.getContext('2d');↩

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var canvas2 = document.createElement('canvas');↩

canvas2.width = canvas.width;↩

canvas2.height = canvas.height;↩

var ctx2 = canvas2.getContext('2d');↩

ctx2.drawImage(document.getElementById('yellow75.png'), 0, 0);↩

ctx.fillStyle = 'rgba(0, 255, 255, 0.5)';↩

ctx.fillRect(0, 0, 100, 50);↩

ctx.globalCompositeOperation = 'difference';↩

ctx.drawImage(canvas2, 0, 0);↩

isPixel(ctx, 50,25, 218,145,146,223, "50,25", "218,145,146,223", 5);↩

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SimpleTest.finish();↩

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});↩

</script>↩

<img src="image_yellow75.png" id="yellow75.png" class="resource">↩

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